Fix a cancellation bug causing a partial image to sometimes be saved

MovieBarCodeGenerator/MainForm.cs

@@ -105,7 +105,7 @@ private async void generateButton_Click(object sender, EventArgs e)
             }
 
             // Register progression callback and ready cancellation source:
-
+           
             var progress = new PercentageProgressHandler(percentage =>
             {
                 var progressBarValue = Math.Min(100, (int)Math.Round(percentage * 100, MidpointRounding.AwayFromZero));
@@ -119,6 +119,7 @@ private async void generateButton_Click(object sender, EventArgs e)
             });
 
             _cancellationTokenSource = new CancellationTokenSource();
+            var cancellationLocalRef = _cancellationTokenSource;
 
             // Actually create the barcode:
 
@@ -140,7 +141,7 @@ private async void generateButton_Click(object sender, EventArgs e)
                 await Task.Run(() =>
                 {
                     result = _imageProcessor.CreateBarCode(inputPath, parameters, _ffmpegWrapper, _cancellationTokenSource.Token, progress);
-                });
+                }, _cancellationTokenSource.Token);
             }
             catch (OperationCanceledException)
             {
@@ -167,6 +168,11 @@ Here is all the info available at the time of the error (press Ctrl+C to copy it
                 _cancellationTokenSource = null;
             }
 
+            if (cancellationLocalRef.IsCancellationRequested)
+            {
+                return;
+            }
+
             // Save the barcode:
 
             try
@@ -248,7 +254,8 @@ void ValidateOutputPath(ref string path)
             string smoothedOutputPath = null;
             if (smoothCheckBox.Checked)
             {
-                smoothedOutputPath = $"{Path.GetFileNameWithoutExtension(outputPath)}_smoothed{Path.GetExtension(outputPath)}";
+                var name = $"{Path.GetFileNameWithoutExtension(outputPath)}_smoothed{Path.GetExtension(outputPath)}";
+                smoothedOutputPath = Path.Combine(Path.GetDirectoryName(outputPath), name);
                 ValidateOutputPath(ref smoothedOutputPath);
             }